Decreased cardiac output in infants of mothers who abused cocaine.

Cocaine increases the level of circulating catecholamines by blocking the catecholamine reuptake receptors. The effect of intrauterine cocaine exposure on cardiac output was studied in 15 full-term newborn infants whose mothers used cocaine during pregnancy. A total of 22 healthy nonexposed full-term infants served as a control group. On the first day of life, cardiac output (183 +/- 12 vs 235 +/- 13 mL/kg per minute, mean +/- SD; P less than .05) and stroke volume (1.3 +/- 0.1 vs 1.9 +/- 0.1 mL/kg, mean +/- SD; P less than .005) were lower and arterial blood pressure (60 +/- 2 vs 41 +/- 2 mmHg, mean +/- SD; P less than .001) higher in the infants exposed to cocaine. On day 2, cardiac output, stroke volume, and mean arterial blood pressure were similar, probably because of the gradual excretion of cocaine and its metabolites by the infant. It was speculated that an increase in plasma norepinephrine levels is responsible for the cardiovascular effects of intrauterine cocaine exposure.